1. Field of the Invention
This invention relates to a painting system for an automobile which includes a plurality of robots for painting an automobile.
2. Description of the Prior Art
In a painting line for automobiles, painting is performed also for various inside faces of an automobile while opening/closing members such as doors, a trunk and a bonnet are held in an open condition.
In particular, as shown, for example, in FIGS. 8(a), 8(b) and 8(c), a plurality of robots including a plurality of painting robots 41, a pair of door openers 42, a trunk opener 43 and a bonnet opener 44 are disposed on the opposite sides of a conveyor along which an automobile 40 is transported.
An engaging pin 48 is attached to an end portion of an arm of each of the door openers 42 and is fitted, for example, into a door groove for a glass window of one of doors 45 of the automobile 40 and drives the door opener 42 to move along a predetermined locus to open the door 45. After then, painting is performed for the inside of the automobile 40 and rear faces of the doors 45 by a pair of ones of the painting robots 41.
Meanwhile, an opener jig 49 is attached to an end portion of an arm of the trunk opener 43 and is engaged with an end portion of a trunk 46 of the automobile 40. Then, when the trunk opener 43 is driven to move along a predetermined locus taught in advance, the trunk 46 is opened. After then, painting is performed for the inside of the trunk 46 and a rear face of the trunk 46 by one of the painting robots 41 corresponding to the trunk opener 43.
Furthermore, another opener jig 50 is attached to an end portion of an arm of the bonnet opener 44 and is engaged with an end portion of a bonnet 47 of the automobile 40. Then, when the bonnet opener 44 is driven to move along a predetermined locus taught in advance to open the bonnet 47. After then, painting is performed for the inside of an engine room and a rear face of the bonnet 47 by one of the painting robots 41 corresponding to the bonnet opener 44.
After painting is performed for the various inner portions of the automobile 40 is such a manner as described above, the doors 45, trunk 46, bonnet 47 and so forth are closed by the door opener 42, trunk opener 43, bonnet opener 44 and so forth, respectively. After then, the automobile 40 is transferred to a next step.
By the way, in such a painting system as described above, while the inside of the automobile 40, the inside of the trunk 46 and the inside of the engine room are being painted, the doors 45, trunk 46 and bonnet 47 are held in the respective open conditions by the engaging pins 48 and opener jigs 49 and 50 provided at the end portions of the arms of the respective robots. Accordingly, paint mist sticks to the end portions of the arms of the openers. Further, paint mist rebounded in the insides of the various portions of the automobile 40 also sticks to the end portions of the arms of the painting robots 19 which perform painting operation.
If such paint mist sticks until it presents an accumulative condition, there is the possibility that operation of any of the openers and robots may be disabled or such paint mist in an accumulative condition may drop, during painting operation, to a painted face and cause a dissatisfactory result of painting
Thus, it is conventionally standardized to wrap a vinyl tape or the like, for example, around an arm portion, a revolute joint or the like of each opener or robot and exchange the vinyl tape during a rest time or for each holiday. For any other portion around which a vinyl tape or the like cannot be wrapped, it is standardized to clean a location to which paint mist sticks with thinner during a rest time or after completion of required operation.
However, since those means involve manual operation by an operator, they are very cumbersome to the operator. Simultaneously, a considerably long period of time is required, which results in deterioration of the production efficiency and increase of the production cost.